Fresh water pre-wash conveyor dishwasher



y 1956 J- D. CLAGUE ET AL 2,746,466

RESH WATER PRE-WASH CONVEYOR DISHWASHER 2 Sheets-Sheet 1 Filed June 8, 1954 10-. ullil II I INVENTORS JAMES D. CLAGUE By ARTHUR n HAAS AfTTORNZYS y 22, 1955 J. D. CLAGUE ET AL FRESH WATER FEE-WASH CONVEYOR DISHWASHER 2 Shets-Sheet 2 Filed June '8. 1954 .w 0 E T mw FRESH WATER PRE-WASH CONVEYOR DISHWASHER James ne and Arthur w. Haas, Rochester, Y,

assignors to Toledo Scale Company, Toledo, Ohio, a corporation of New Jersey Application June 8, 1954, Serial No. 435,332 7 1 Claim. Cl. 154-72 This invention relates to conveyor-type dishwashing machines, and moreparticularly to improved means for prewashing dishes in such machines.

The effective and eco'nomicalcleansing of dishes in conveyor-type dishwashing machines requires a minimum of three operations, namely, a fresh cold or tepid water pre-wash to flush the bulk of particles of food scraps and other soil from the dishes and to wet the dishes so that they may bewashed with aminimum of washing solution, awash to flood the dishes with a cleansing solution, and arinse to remove the cleansing solution and sanitize the dishes Preferably, for low cost, the rinse is a two-inone rinse and sanitizing operation producedby spray devices using only fresh'hot water which both removes the water directly from a kitchen water lineto save the cost of heating pre-wash Water and to save the cost of motordriven pumps to supply pre-wash water under pressure.

I Efficient pre-rinsing and complete wetting of all the dishes passing through thepre-wash space requires that the prewash water be sprayed through slotted devices, such as slotted nozzles, so that an extensive pre-wash spray area is produced. 'Such slotted devices, however, are inefiicient in areas having water under'high pressure in the kitchen, line, since the slots atomize water under high pressure.

The principal object of this invention is to provide, in' aconveyor-type dishwashing machine having successive prewash, wash, and rinse and sanitizing spaces, slotted pre-wash devices supplied with fresh coldor tepid waterat substantially less than normal city water line pressure.

Another object of the invention is to provide, in such .a dishwashing machine having slotted pre-wash devices supplied with fresh cold or. tepid water at substantially less than normal city water line pressure, means for. supplying only fresh hot water to rinse. and sanitizing devices Within the rinse and sanitizing space.

These and. other objects and advantages will be ap:

' parent from the following description of a preferred form of the invention.

According to the invention, conveyor-type dishwashing machines having successive pre-wash, wash, and rinse and sanitizing'spaces are provided with slotted pre-Wash devices and means including flow control valves for supplying cold or tepid fresh Water at substantially less than normal pressure to the slotted pre-wash devices.

The cold or tepid fresh water for the pre-wash is supplied from a city water line through a flow control valve calibrated to flow gallons to gallons of water per =minute.

Preferably the fresh water for the pre-wash is supplied as tepid water, i. e., water arm enough not to "ice v congeal grease but cold enough not to congeal or set albuminous material such as eggs.

Preferred embodiments are illustrated in the accompanying drawings:

In the drawings:

Figure I is a front elevation view of a dishwashing machine embodying the invention, parts being broken away. a

Figure His 2. plan view taken alongthe line II-II of Figure I.

Figure III is an end elevational view of the machine shown in Figure I.

Figure IV is a front elevational view of a second dishwashing machine embodying the invention.

Referring to the drawings in detail:

The dishwashing machine shown in Figures I, II and III comprises a rectangularly shaped cabinet 1 including.

' an entrance 2 at one end, an exit 3 at the other end, and,

' line.

in succession, a pre-wash space 4, a wash space 5, and a rinse and sanitizing space 6. Liquid is supplied to sets of wash spray tubes 7 and rinse spray tubes 8 which tubes '1 and 8 are slotted so that the sprayed water completely covers all of the dishes passing through the machine within the spaces 5 and 6. Pumps 9 driven by a motor 10 supply liquid from a wash tank 11 and a rinse tank 12 to the wash tubes 7 and the rinse tubes 8 respectively.

Fresh hot water from a source outside of the machine is supplied under pressure through pipes 13 to rinsing and sanitizing devices 14 each comprising a plurality of removable caps 15 for easy cleaning. The used hot water is captured and is recirculated in the rinse tank12 to aid in replenishing the rinse water supply. The rinse tank 12 is initially filled with water by means of a nonsyphoning open tank fill 16 comprising a water chute 17 and a filling pipe 18 having a gap between the delivery end of the pipe 18 and the water level in the rinse tank 12 to eliminate the possibility of water from the rinse tank being syphoned back into the fresh water supply The tank opening, seen through the water chute 17, is also a visual water level gauge. To replenish losses and to heat the rinse water, a rinse tank steam injector 19 of the silent type is provided.

Fresh cold or tepid water from a source outside of the machine (city water line) flows through a flow control valve 20 (Figure III) calibrated to flow-10 to 15 gallons per minute, which is at substantially less than normal pressure, i. e., city water line pressure. The water flows from the flow control valve 20 through pipes 20b to pre-wash devices 21 each comprising a plurality of nozzles 22 slotted to provide an extensivepre-wash spray area for eificient pro-rinsing and complete wetting of all the dishes passing through the pre-wash space. It is necessary that the pressure of thewater be reduced by the flow control valve 20 so that the dishwashing ma- .chine may be installed in those areas having high city water pressure, since the slotted nozzles 22 atomize water under high pressure. It is preferable that. the fresh water for the pre-washbe supplied as tepid water, i. e., water warm enough not to congeal grease but cold enough not to congeal or set albuminous material such as eggs. The used pre-wash water is captured in a pre-wash tank 22 and is allowed to escape down a drain 23. I

To take advantage of the fact that dishes coming from the pre-wash space 4 are wet and therefore need and use up only a small quantity of washing solution, the washing solution in the wash tank 11 is replenished and heated with steam supplied by a wash tank steam injector 24 of tank 11 and the rinse tank 12, overflow stand pipes 26 Patented May 22, 1956 chains 29 extends through substantially the full length of the cabinet 1 and supports and moves trays of dishes through the various spaces 4, 5 and 6 and past the several pre wash devices 21, spray tubes 7 and 8, and rinse and sanitizing devices 14.

When a tray containing soiled dishes is placed upon the conveyor through the entrance 2 and an electrical control button 30 is depressed, the conveyor begins moving and liquid sprays from the spray tubes 7 and 8 within the spaces 5 and 6. As the trays start into the pre-wash space 4, thetrays engage an arm 31 of a solenoid valve causing fresh cold or tepid water to be sprayed from the slotted nozzles 22 down onto the dishes and up and onto the dishes in the trays which trays are sufficiently open at the bottom to permit entrance of the spray. When the trays have passed the arm 31, the solenoid valve is automatically closed. Similarly, as the trays pass into the rinse and sanitizing space 6, the trays engage an arm 32 of a solenoid valve causing fresh hot water to be sprayed from the rinse and sanitizing devices 14 down onto the dishes and up and onto the dishes in the trays. When the trays have passed the arm 32, its valve is automatically closed in order that hot water may be conserved. During the operation, water is prevented from escaping through the entrance 2- and the exit 3 of the cabinet 1 by means offiexible nylon curtains 33- hu-ng near the entrance and the exit which curtains are readily moved out of their normal positions by a tray or dish. Also, during the operation; the spraying liquid in the several spaces is prevented from substantially commingling'by means of steel partitions 33b fixed to the ceiling of the cabinet 1.

The bulk of particles of food scraps and other soil removed from the dishes in the pre-wash space 4 by the cold or' tepid water spray is caught and retained in a removablereceptacle 34 having a perforated screen 35 located below the lower slotted nozzles 22 within the pro-wash spaee 4. Access to the receptacle 34' may be had throughan entrance closed by a door 36 engaging the side of the cabinet 1 near the entrance 2. All parts of the pre-wash space 4* are accessible for cleaning when the removable receptacle 34 istaken from the machine. Access tothe wash space 5 and to the rinse and sanitizing space 6, also containing removable receptacles having perforated screens 37 and 38" below their respective lower spray tubes maybe obtained through a door 39 engagingthe side of the cabinet it near the middle of the' cabinet and a door 40 engaging the side of the cabinet near the exit 3.

A second dish-washing machine embodying the invention is shown: in Figure lV. This machine is an improvement over the machine hereinhefore described, since this machine also effectively cl'eans dishes but is of lower cost to' manufacture. The machine shown in Figure IV is very similar to the machine hereinbefore described, exceptthe rinse and sanitizing space is simplified. The means: for supplying hotwater to the rinse and sanitizing devices shown in- Figure lV supplies only fresh hot water. The rinse isa' two-in-one operation produced by spray devices using only fresh hot water which both removes the cleansing solution and sanitizes the dishes, yet saves. the cost of a motor driven pump supplying recirculated rinse water under pressure.

The dishwashing machine shown in Figure IV'cornprises a' rectangularly shaped cabinet 41 including an entrance 42 at one end; an exit 43 at the other end, and, in succession, a pro-wash space 44,, a wash space 45, and

a rinse and sanitizing space 46. Liquid is supplied to sets of wash tubes, 47 slotted so that sprayed water completely covers all of the dishes passing through the machine within the wash space 45. A pump 48 driven by a motor 49 supplies liquid from a wash tank 50 to the wash tubes 47 which tank 50 is initially filled with water by means of a pipe 51 and is emptied by means of a drain 52. To replenish losses and to heat the wash water, a steam injector 5 3 of the silent type is used.

Fresh hot water from a source outside of the machine is supplied under pressure through pipes 54 to rinsing and sanitizing devices- 55 which are like the rinsing and sanitizing devices 14 hereinbefore described. The used water is allowed to escape down a drain 56.

Fresh cold or tepid water from a source outside of the machine (citywater line) flows through a flow control valve like the flow control valve 20 shown in Figure Ill. Both of the machines shown in Figures I and IV have the same right end elevational views, therefore, Figure HI which is an end elevational view of the machine shown in Figure I may also be referred to in reference to the machine shown in Figure IV. The water flowsfrom the control valve through pipes 57 to pre-wash devices 58. which are like the pre-wash devices 21 hereinbei ore described. The used pre-washwater is allowed to escape down a drain 59.

A- conveyor comprising a pair of spaced apart sprocket chains 60 extends through substantially the full length of the cabinet 41 and supports and moves trays through the various spaces 44, 45 and 46 and past the several pref wa-shzdevices 58, wash spray tubes 47 and rinse and sanitizing devices 55. Operation. of the machine is like the operation of the machine shown in Figures I, II and 11 1 and hereinbefore described. During theoperation, water is prevented from escaping through the entrance 42 and the exit 43 of the cabinet 41 by means of flexible nylon curtains 60a hung near the entrance and the exit which curtains are readily moved out of their normal position by a tray or dish. Also, during the operation, the wash liquid and the prcrwash water are prevented fromsuhstan-tial ly commingli'ng by means of a steel partition 61* fixedto the ceiling of the cabinet 1.

Various modifications may be" made in specific details of construction without departing from the spirit and scope of the invention.

Having desc'ribed the invention, we claim:

In a dishwash-ing machine, in combination, a cabinet having afront entrance opening and a rear exit opening, successive pr'e-wash, wash, and rinse spaces within the cabinet, means within the cabinet for transporting articles to be washed through the spaces from the entrance opening to the exit opening, slotted pre-wash devices within the pre-washspace, apipe-connected to the pre-wash devices for supplying fresh water from a source outside of'themachine tothe pro-wash devices, a flow control valve in the pipe for limiting the how of the fresh water supplied to the pre-wash devices to less than 15 gallons per minute, rinse devices within the rinse space, means communicating withthe rinse devices for supplying fresh heated water only thereto, a liquid supply tank below the wash space, and means for conducting liquid under pressure from thettank into; the wash space.

References Cited in the file of this patent UNITED STATES PATENTS Porter Nov. 6, 1951 

